1. Field of the Invention
This invention pertains to a dye composition, an apparatus, and a method of using the same.
2. Description of the Prior Art and Objectives of the Invention
Many solvent and aqueous compositions and procedures for dyeing yarns, fabrics and other textile structures composed of polyesters, polyamides, polyacrylics and the like have been described over the years as evidenced by U.S. Pat. Nos. Re. 27,773; 3,467,474; 3,518,734; 3,530,214; 3,558,260; 3,770,528; 3,771,949; 3,943,105; 4,047,889; 4,055,971; and 4,115,054. Each of these procedures encompasses limitations however. Some are slow and inefficient; some require special pressure vessel equipment; some require volatile and possibly flammable solvents; some cause air or liquid pollution; some are hard to control sufficiently to assure consistent and uniform product quality; and some are expensive to operate.
One of the hardest fibers or fabric to dye is polyester, even though it is widely used in the industry. Experiments with high boiling point solvents, such as tri-ethylene glycol (TEG) acknowledged that this solvent is excellent for disperse and acid dyes. Removal or separation of the dye from the solvent is also accomplished without difficulty, and the elimination of any crocking tendency is straight forward and efficient. Problems arise however, because traces of TEG are left in the textile structure. These traces contain ether linkages which have a negative effect on light fastness. Likewise, experiments with xe2x80x9cpurexe2x80x9d dye in press cake form were also unsatisfactory.
Therefore, with the above considerations in mind it is an objective of the present invention to provide a dye composition which does not contain ether linkages.
It is a further objective of the present invention to provide a dye composition which suitably, uniformly dyes polymeric textile structures repeatedly over extended periods of time without the disadvantages of prior dyeing compositions and techniques.
It is yet a further objective of the present invention to provide a dyeing process which uses glycerin and a dye in its press cake form.
It is still a further objective to provide a method for dyeing which operates at a temperature above the melting point for specific dyes, but below their sublimation points.
It is an additional objective to provide a method for dyeing which works with dyes having multiple melting points.
It is another objective to provide a dye composition which contains 99.7% pure glycerin.
It is yet another objective to provide an apparatus which recycles the dye composition.
It is still another objective to provide a dyeing apparatus which directs the textile structure through a flowing dye composition where both the textile structure and the dye composition move at the same rate so as not to stress the textile structure.
It is a further objective to provide a dyeing apparatus which scours the textile structure before and after the textile structure is dyed.
It is still a further objective to provide a dyeing apparatus which recycles and repurifies the water used to scour the textile structure.
It yet a further objective to provide a method for dyeing a textile structure which incorporates elements of the dyeing apparatus and the dye composition.
It is another objective to provide a dyeing apparatus which operates between 160xc2x0 and 190xc2x0 C. for the first part of the dyeing step and then operates at a lower temperature for the remaining part of the dyeing step.
These and other objectives and advantages will become readily apparent to those skilled in the art upon reference to the following detailed description and drawings.
The invention herein pertains to a dyeing composition wherein the composition is made from synthetic glycerin which is greater than 99% pure such as 99.7% pure or greater and a dye, wherein said dye is placed in said glycerin in press cake form, and the resulting composition is then heated to 160xc2x0 to 190xc2x0 C. so as to form a dye composition which has a uniform consistency. The dye can be added at various levels depending on the darkness of the dyeing composition desired. The preferred range is 0.1 grams to 4.0 grams of dye per liter of glycerin, with 0.25 grams being best suited for a light dye, 1.1 grams being best suited for a medium dye and 2.0 grams being best suited for a dark dye. The preferred dyes are disperse orange 30, disperse blue 27 and disperse yellow 86. These are sold by a number of companies and are standard within the trade.
This dyeing composition is then used in an apparatus which is well suited to dyeing textile structures such as yarn, threads, fibers, fabric and the like. The preferred apparatus unwinds the textile structure and feeds it into a twenty foot, or 6.1 meter, long prescour vessel by appropriate conventional guide rolls. The prescour vessel is filled with a scouring composition which removes oils, dirt and debris from the textile structure. The textile structure is then fed through a dewatering device and heated by a conventional godet heater for complete drying. While a godet heater is preferred, any comparable electrical induction heater could be used as is well understood. While the above dimensions are suitable for a pilot plant, large scale installations may be two and a half to three times larger as desired.
Thereafter, the textile structure is then fed into a non-pressurized dyeing vessel which is filled with the dye composition described above. The textile structure is moved through the dye vessel in a heated portion for approximately 25 feet or 7.62 meters, and then through a cooler portion of the dye vessel for approximately 5 feet or 1.52 meters. The dye composition flows through the dye vessel at the same rate as the textile structure so that no stresses occur on the textile structure. The textile structure is then passed through a second dewatering device and into an approximately twenty foot dye scour vessel by appropriate guide rolls. Excess dye is cleaned from the textile structure. Next, the textile structure is fed through a third dewatering device and into an approximately twenty foot long post scour vessel where detergents are used to further clean the textile structure. After this cleaning, the textile structure is dewatered a fourth time and is thereafter heated by a conventional godet heater. Lastly, the textile structure, if a yarn, is oiled and wound as is conventional.
In the first section of the prescour vessel, the textile structure is cleaned by counter current flow through a mixture of purified water and a scouring agent such as Henkel Chemical CS-605 and is agitated ultrasonically at a temperature of 90xc2x0-95xc2x0 C. The scoured textile structure is then rinsed in the last section of the prescour vessel by counter current flow through purified water at about 90xc2x0 C. and continued ultrasonic agitation. The scouring solution is pumped to a receiving tank where it is stored until the water can be purified via usual ultra or hyperfiltration techniques for reuse.
The dye vessel contains the dye composition which has been heated to about 160xc2x0 to 190xc2x0 C. The first portion of the dye vessel is jacketed with hot oil or other comparable heat transfer medium so that very uniform temperatures can be achieved. Optional ultrasound agitators may also be used at this stage. The second portion of the dye vessel is also jacketed, but with cooling water so that the dye composition is brought to a temperature of about 100xc2x0 to 140xc2x0 C. This xe2x80x9cfreezesxe2x80x9d and sets the dye in the textile structure. The second dewatering device returns any excess dye composition to the dye vessel. The excess dye composition is transported to the dye composition storage tank where it can be sampled, adjusted as required, reheated and recirculated through the process. One of the advantages of the nearly pure glycerin is that it does not change color after repeated heatings and coolings which is a failing common to less pure glycerin. Likewise, no odor is apparent from the ultra pure glycerin use. Both odor and discoloration are undesirable as they affect the ultimate salability of the textile structure.
The dye scour vessel removes any remaining excess dye composition from the textile structure by counter current flow by purified water which has been heated to approximately 90xc2x0 to 95xc2x0 C. and ultrasonic agitation. Water from the dye scour vessel is pumped to a receiving tank where it is stored until the water and dye composition can be separated by ultra or hyperfiltration techniques for reuse.
The post scour vessel removes any trace of dye composition that may inadvertently remain on the textile structure, and assures no crocking problems. The first half of the post scour vessel thoroughly cleans the textile structure by counter current flow through a mixture of purified water and a scouring agent such as Henkel Chemical CS-605 at a temperature of 90xc2x0 to 95xc2x0 C. and ultrasonic agitation as is desired or required. The second half contains purified water to rinse the textile structure.
The method of using the apparatus follows the nature of the apparatus closely and consists of unwinding the textile material, tensioning it on guide rolls, and cleaning any winding oil in a prescour vessel. The next steps comprise dewatering the textile structure and heating the textile structure prior to introduction into a heated dye vessel where dyeing and cooling occur. The textile structure is then dewatered again and cleaned in the dye scour vessel. The textile structure is dewatered a third time and introduced into a post scour vessel for final cleaning, dewatering and heating prior to oiling the structure if a yarn and rewinding. Also included in the method are the steps of recycling the fluids used to carry out the cleaning and dyeing steps.